Hard starting when cold, for the 10,000th time!

I live in san Diego so for what it's worth,
Check the voltage drop on both the ground wire from the battery and the b+ wire on the battery to the starter. Low voltage will cause a slow crank and start.

This is a very easy test. Place the red lead of your volt meter on the engine and the black lead on the neg side of the battery. Have someone crank the engine. Normal readings are about 600mv or 0.600v. The higher the number the higher resistance in the cable or conector. Sometimes just cleaning the ground wire will bring everything into spec.

Next test the pos wire, red lead onto the pos battery and black lead on large post of starter. Same spec same test.

If you mix up the leads its ok you will just get a negitve number
good luck.

Raxum said:

I live in san Diego so for what it's worth,
Check the voltage drop on both the ground wire from the battery and the b+ wire on the battery to the starter. Low voltage will cause a slow crank and start.

This is a very easy test. Place the red lead of your volt meter on the engine and the black lead on the neg side of the battery. Have someone crank the engine. Normal readings are about 600mv or 0.600v. The higher the number the higher resistance in the cable or conector. Sometimes just cleaning the ground wire will bring everything into spec.

Next test the pos wire, red lead onto the pos battery and black lead on large post of starter. Same spec same test.

If you mix up the leads its ok you will just get a negitve number
good luck.

Click to expand...

So I'm not crazy. I have mentioned this before and received luke-warm responses. Probably because I wasn't quite sure I was right though. Thanks for the post.

OK - car starts as normal but REALLY chugs (and not beer). Sort of acts like someone is reving the engine by pressing up and down on accelarator but it is very low like it might die. After driving and warming up, it runs fine. Outside temps 45 degrees!

Any ideas?

Got 90K, DBW did timing belt and no codes showing. I do have some electical issues - door/key buzzer doesn't work, courtesy lights don't come on. These have been this way a long time so don't think related.

Thanks

My CEL GP saga continues- - -

After months of waiting while the dealers mechanics struggled with my car i have finally received a call to let me know they have figured out what's wrong. After replacing almost everything and spending more than 20 hours troubleshooting the conclusion is that the ECM needs to be replaced. They offered to install it for free-but the part itself is $1500.

I said no and picked the car up the next day. I am searching for a used ECM part #028906021JB. The fault is intermittent and it's warm out so right now the car is running fine-the CEL goes out when I start the engine and I have no complaints about it.

If anyone has a source for -reasonable- used parts they'd like to share I'd appreciate it. A guy on ebay sells ECMs but so far hasn't got the one I need. I don't want to spend a lot on this because i may not be keeping the car.

Thanks much

Since the ECU fault is intermittent and apparently temperature sensitive, there's a good chance the cause is a cold solder joint on the PCB.

I would try to fix it - careful visual inspection of the PCB under a loupe, and re-flow any dull solder joints.

Simon

I'd contact Jeff @ Rocketchip or one of the other chip vendors, they often have resources to rebuild/repair ECUs.

alloztome said:

After months of waiting while the dealers mechanics struggled with my car i have finally received a call to let me know they have figured out what's wrong. After replacing almost everything and spending more than 20 hours troubleshooting the conclusion is that the ECM needs to be replaced. They offered to install it for free-but the part itself is $1500.

I said no and picked the car up the next day. I am searching for a used ECM part #028906021JB. The fault is intermittent and it's warm out so right now the car is running fine-the CEL goes out when I start the engine and I have no complaints about it.

If anyone has a source for -reasonable- used parts they'd like to share I'd appreciate it. A guy on ebay sells ECMs but so far hasn't got the one I need. I don't want to spend a lot on this because i may not be keeping the car.

Thanks much

Click to expand...

www.car-part.com will have lots of them available. You can search locally, or nationally if the place you find one will ship. Prices usually range from $100 - $500.

EDIT: Just did a search and if you have a 97 or early 98, it looks like there are only 3 available. One for $175 and the other 2 have no price. The one in Tottenham is only 20 min from me. I tried calling for a price, but they closed at 5. I'll call again in the morning.

If this dosn't work out, then the earlier recomendation to have Jeff fix it is a good one. Only problem being that you will be without your car for a couple of days. Thats why a used one might be a better possibility.

LMK if you want me to look into getting the one here and sending it down for you.

please help me

I'm from the UK and have a Ford Galaxy people wagon, it's fitted with the vag 1.9 tdi AVG engine code [110bhp] Problem i have is poor starting from cold as in it won't start unless you give it some throttle to coax it into life as it were. First off i checked the glow plugs, yep fine, but theres no live feed to the plugs, soo i checked fuses which brought me back to glow plug relay where i have a think live in, thick live out, black ignition fused live and a yellow wire that goes to pin 50 on the ecu.

Trouble is i need a earth from the ecu to power up the relay/glow plugs which i am not getting. Now i've read on here if temps are below 40F the glows don't work, but where does it record the temp at? ambiant air temp? fuel temp? coolent temp? i've read somewhere that the ecu also moniters manifold pressure, is this true?

I've tried the unplugging coolent temp switch but this makes no difference.

It's bringing up no codes at all and once first started it starts & runs excellent. The only thing is it got jumped off about three months ago which spiked the fuel pump so this has been changed, and it's since then it's been dodgy starting.
Which leaves three possible additional faults as far as i can see;
1, the ecu also got spiked
2, the replacement pump wasn't a brand new item so it's possible that may be broken
3, could the pump timing be a gants cock out? And would that effect cold starting only?

Also those of you who say your timing is within those limits 770-1250 for example, what does that mean and how do you get that info, is that accessable through vagcom?

P2B said:

Since the ECU fault is intermittent and apparently temperature sensitive, there's a good chance the cause is a cold solder joint on the PCB.

I would try to fix it - careful visual inspection of the PCB under a loupe, and re-flow any dull solder joints.

Simon

Click to expand...

I have mixed thoughts on the temp sensitivity- The dealer had it in the shop for a good month of over 40 degree AM's and the CEL remained on after starting-sometimes it came on minutes after the car was being driven, sometimes after the car had been started a few times during the day. Inconsistent.

They tell me that when it was in the shop and running, the glow plugs cycled on-that is what they base the ECM fault on. I have had it back for 3 weeks now and it has been fine-the CEL light goes out when I start the car and has not come back on once.

I'm not doubting them, I'm just-doubting them.

While I'm at it let me show my ignorance again. What does PCB stand for? I'm really not good with abbreviations-when someone told me what ECM stands for I had on of those hit myself in the head and say "I knew that" moments.
Thanks

tadc and Wingnut-thanks for the info and link. On eBay a ECM with fuses and harness from a '98 tdi just went for $202.50 US -more than I wanted to pay.

My tdi is a late '98 and has other clutch/flywheel/transmission issues I am drafting another thread-looking for opinions and options about it.

btw-those "handy how-to's" are amazing. Unfortunately, I live in a condo and don't even change my own oil anymore

JamesUKPAF said:

Trouble is i need a earth from the ecu to power up the relay/glow plugs which i am not getting. Now i've read on here if temps are below 40F the glows don't work, but where does it record the temp at? ambiant air temp? fuel temp? coolent temp? i've read somewhere that the ecu also moniters manifold pressure, is this true?

I've tried the unplugging coolent temp switch but this makes no difference.

It's bringing up no codes at all and once first started it starts & runs excellent. The only thing is it got jumped off about three months ago which spiked the fuel pump so this has been changed, and it's since then it's been dodgy starting.
Which leaves three possible additional faults as far as i can see;
1, the ecu also got spiked
2, the replacement pump wasn't a brand new item so it's possible that may be broken
3, could the pump timing be a gants cock out? And would that effect cold starting only?

Also those of you who say your timing is within those limits 770-1250 for example, what does that mean and how do you get that info, is that accessable through vagcom?

Click to expand...

James- The glow plugs should light up for 20-30 seconds when the Coolant Temp Sensor is unplugged, come hell or high water(assuming your Ford works the same as our US TDIs). The ECU does monitor manifold pressure, assuming you have a turbo on yours.

Pump timing could cause bad starts, but you're not seeing GP action with the CTS unplugged, so I'd bark up that tree first. You said that unplugging it makes no difference, but you didn't specify how you're coming to that conclusion- did you check for voltage on the harness, or did you just mean that it still starts hard with the CTS unplugged?

alloztome said:

What does PCB stand for?

Click to expand...

Printed Circuit Board

P2B said:

Printed Circuit Board

Click to expand...

D'oh!!!! That is too funny-I worked for a company that made them. I have never referred to them as PCB's. I believe PCB's are also a toxic waste.

alloztome said:

D'oh!!!! That is too funny-I worked for a company that made them. I have never referred to them as PCB's. I believe PCB's are also a toxic waste.

Click to expand...

polychlorinated biphenyls - great coolant and lubricant for electrical equipment and transformers. Byproduct of Agent Orange and other chemical process production. Bad contaminant measureable all the way up to the Artic, with an affinity for sticking to fat cells for a long, long time.

RT1 said:

polychlorinated biphenyls - great coolant and lubricant for electrical equipment and transformers. Byproduct of Agent Orange and other chemical process production. Bad contaminant measureable all the way up to the Artic, with an affinity for sticking to fat cells for a long, long time.

Click to expand...

For a second there, I thought you were describing White Castle hamburgers.

tadc said:

James- The glow plugs should light up for 20-30 seconds when the Coolant Temp Sensor is unplugged, come hell or high water(assuming your Ford works the same as our US TDIs). The ECU does monitor manifold pressure, assuming you have a turbo on yours.

Pump timing could cause bad starts, but you're not seeing GP action with the CTS unplugged, so I'd bark up that tree first. You said that unplugging it makes no difference, but you didn't specify how you're coming to that conclusion- did you check for voltage on the harness, or did you just mean that it still starts hard with the CTS unplugged?

Click to expand...

With coolant temp unplugged i had no voltage at the harness.

I've adjusted the pump a bit and it seems ok now so problem solved, but i'm still interested in where the ecu moniters temperture from to decide whether or not it should operate the glow plugs, is it just coolant temp? or fuel temp/ambiant air temp aswell?

Not positive but I believe it's just coolant temp(which is a good indicator of combustion chamber temp, which is the critical factor here).

tadc said:

Not positive but I believe it's just coolant temp(which is a good indicator of combustion chamber temp, which is the critical factor here).

Click to expand...

Its also atmospheric pressure, as measured by the MAP sensor. Cars at high altitudes will glow much longer than cars at low altitudes, regardless of the temps.

Wingnut said:

Its also atmospheric pressure, as measured by the MAP sensor. Cars at high altitudes will glow much longer than cars at low altitudes, regardless of the temps.

Click to expand...

I'm glad you mentioned that - so if someone were to reduce the MAP output in order to create a boost bleed electronically, a side effect would be increased glow times.

Does this apply to A3 cars?

Simon

Hart to start when cold

My fuel pump was leaking. After that was fixed I had no issues anymore with starting when cold.

Am very impressed with your apparent knowledge diesle engines. My 05 Passat 2.0TDI is now experiencing hard cold start conditions. This is the second winter for it and just lately getting worse. Today with temps at 28f it took a long cranking cycle to ignite the engine, with much black smoke immediately after starting. suspecting glow plug burn time but in reading your explanation about injection timing puts yet another light on the subject. Thanks for the very detailed information it is much appreciated.
Made an appt today with the dealer here in central PA, next Tuesday I will see what they have discovered. I hope the mechanics there are as capable as you seem to be. But I have much reservations about them from past experience.

gusII said:

Made an appt today with the dealer here in central PA, next Tuesday I will see what they have discovered. I hope the mechanics there are as capable as you seem to be. But I have much reservations about them from past experience.

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How far are you from Sunbury PA? Why not contact Metal Man?
http://forums.tdiclub.com/member.php?u=6610

Many tdiclub members travel down from New York to have him install new timing belts. Your problem isn't serious, but it's better to have a guru fix it instead of letting some dealership tech practice his meager troubleshooting skills.

Thanks for the info, I am about 2 hours west of Sunbury and it is a beautiful drive there. If the problem can not be fixed at the dealer I will certainly look this man up. I agree it is always better to pay an epxert to fix the problem than to pay a novice to learn at ones expense. The car is still under warranty so I will go that route for now. Again today with temps at 28 degrees it took three attempts to start the engine. I can not imagine living where it is really cold and driving one of these PD TDIs. This one is a fair weather diesel would do fine in the South. All winter I noticed it getting worse, thought perhaps it was the new fuel so I installed a Frost Block heater that worked beautifully when energized, but with temps just below freezing I did not think I would need the block heater and judging from what everyone is telling me, I should not need to use it at these temps.
It is good to know that there are real mechanics out there, not just wanna bees.

Hi all,
I'm having problems with my 5 cyl tdi, Cold weather starting Is giving me loads of white smoke, it's gone after the engine is warm.

It's an AEL engine in an audi a6 though it's the same as an VW van 5 cyl.

I have already changed the glow plugs, 1 was dead, changed the glow plug temp sensor and the gauge temp sensor.

I have 12v at each end of my GP harness.

Had the timing belt changed and VAG com show's timing is spot on to slightly advanced in the tdi timing.

Anyone any other ideas?

Thanks

Are you sure that timing is being taken in basic settings mode? If not, it's not a good reading for starting.

What is the ambient temp when this happens? Did the problem start after the timing belt was changed? How long does it crank before it starts?

White smoke means incomplete burn - could be dirty/clogged/leaking injectors.

Simple question - would a bad (or poor) glow plug harness cause a hard cold start?

I have a new battery and timing is right in the middle of the graph - on the blue line. All the glow plugs are at .9 ohm, the glow plug relay is ok, and I'm getting 12 volts through the harness. But, I do have a CEL for a bad glowplug, which means that the harness isn't making a good connection to the glowplugs. I've tried deoxit a couple of times, but it hasn't helped.

Thanks - Ron.

Maybe... but in my experience the intermittent CEL caused by the harness has never caused a starting issue.

The harness is cheap and easy to replace, so I'd just do it.

Re: timing, the timing should be well above the centerline for good cold starts.

tadc said:

Are you sure that timing is being taken in basic settings mode? If not, it's not a good reading for starting.

What is the ambient temp when this happens? Did the problem start after the timing belt was changed? How long does it crank before it starts?

White smoke means incomplete burn - could be dirty/clogged/leaking injectors.

Click to expand...

Temp is low to mild -3c to 12c (UK winter)

I'm sure the timing is in basic settings, as it won't let you into the tdi timing unless you are.

Before the timing belt was changed the timing was way advanced it was showing 130 instead of 55 on the tdi timing graph, now it's around 57-60.

I also checked the mesuring block 4? to see the actual, requested and duty % and they were all in spec 2.2 degress and 5-7% load.

Cranking the car can take two or three attempts for it to start, around 5 to 10 seconds, when warm it starts 1st turn of the key within a second or two. The engine did stop the other night after starting but re started after another 5 sec crank. temp was 3c.
The cars power seams low when 1st starting but improves after 30 -60 seconds, once warm it flies!

The car has done 230k miles and the head, water pump and turbo have been replaced before I had the car, I have replaced the glow plugs.

I have ordered a set of new nozzles for the car as that was the next thing on my list.

MPG is great on a run I get low to mid 40's, though short school drop journeys it's dire 22-30 mpg, thought it's a quattro so that doesn't help.

volkswarren said:

Temp is low to mild -3c to 12c (UK winter)

I'm sure the timing is in basic settings, as it won't let you into the tdi timing unless you are.

Before the timing belt was changed the timing was way advanced it was showing 130 instead of 55 on the tdi timing graph, now it's around 57-60.

I also checked the mesuring block 4? to see the actual, requested and duty % and they were all in spec 2.2 degress and 5-7% load.

Cranking the car can take two or three attempts for it to start, around 5 to 10 seconds, when warm it starts 1st turn of the key within a second or two. The engine did stop the other night after starting but re started after another 5 sec crank. temp was 3c.
The cars power seams low when 1st starting but improves after 30 -60 seconds, once warm it flies!

The car has done 230k miles and the head, water pump and turbo have been replaced before I had the car, I have replaced the glow plugs.

I have ordered a set of new nozzles for the car as that was the next thing on my list.

MPG is great on a run I get low to mid 40's, though short school drop journeys it's dire 22-30 mpg, thought it's a quattro so that doesn't help.

Click to expand...

That many miles and rebuilt head makes me wonder if you have good compression, but also the nozzles may be shot too. That's probably a good place to start.

volkswarren said:

......The engine did stop the other night after starting but re started after another 5 sec crank. temp was 3c......

Click to expand...

IMO, the ECM does not turn on the glow plugs at the right temperature. I have heard of so many starting problems right above the freezing mark. If it is colder than 0*C, then the cars would start fine because they are getting glow. But, for some reason, they don't glow just above freezing and take a few extra cranks. You can overcome this issue by extending the glow time with Vag-com. Although, I must admit, I have no clue on how to do it on your AEL engine, or if its even possible. But on an ALH engine, you can go to Engine....Login(12233)......Adaptations.....group 012 and change the value to 32650. This extended my glow time by about 5 seconds and raised the threshold at which it starts to glow to a higher temperature.

I hope this helps.

We think the car has been chipped at some point, though my brothers AAT(115bhp 1995) engine happly logs in with 12233, though the AEL(140 1997) engine wont. The AAT is the earlier lower powered 5 cyl tdi, smaller injectors are main difference.

Would the remap effect this?